I'd like to share a quote from Michael Crichton's book Jurassic Park:
Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
This is instructive, not just of the incredibly highbrow prose I read, but perhaps also the situation you now find yourself in. If your humble author has done even a half decent job, you should have gained an understanding of most of the major functionality and techniques available when using Sass and Compass to author style sheets.
Just be mindful that although we have these skills and techniques at our disposal, this doesn't necessarily mean they are right to use all the time.
Practically, we have already considered that things such as over-nesting rules can produce anti-patterns in our generated code. In the same vein, consider whether other practices that are now more easily achievable with Sass and Compass are actually the right choice. In-lining a 1 MB image as a data URI in your CSS wouldn't be a smart...